Electric interlocking system



Jan. 16, 1923.

J. c. LINDNER.

ELECTRIC INTERLOCKING SYSTEM.

3 SHfiETS SHEE] I.

E|LEU FEB-15.1919- Jan. 16, 1923.

3 SHETSSHEET 2.

flLfU FEB-15.1919.

Jan. 16, 1923.

i 1. c. LINDNER.- ELECTRIC INTERLOGKiNG SYSTEM 3 SHEETSSHEEI 3.

HLE D FEB-15.1919.

Patented Jan. 16, 1923i UNITED STATES PATENT OFFICE.

JOHN C. LINDNER, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SEGNAL COMPANY. OF ROCHESTER. NEW YORK .A COEPORATION OF NEW YORK.

IELECTBIC INTERLOCKING SYSTEM.

Application filed February 15, 1919.

To a w mm it may concern:

lie it known that I, dorm t. lnNnNnn, a citizen ol the l niterl Statem and a resident of the city 0' Rochester, in the county of Monroe and f ltate oi" Llcw York. have invented a new and useful Electric interlocking System, oi which the following is a spe ification.

This inrcnt ion relates to electric interlockinn rysteins For railnnys, and more particularl to an interlockiim system (11 the type employing: the so called dynamic, indication principle.

'lhis illIlPlh'ittlOll is a continuation in part oi my two prior applications, Serial No. 'ltllfifil. tiled Jnne (l 1916. and Serial No. llinz'rttg tiled August 1111916.

lllcctric intcrlocl-cinn systems en1ployin the dynamic indication principle are well known in the art and have been used to a largercxtent. b nch systems. however employ direct current for operating switches. signals. derails, and the like, conveniently termed Functions; and the indication current given d \'1.1an1ically by each function also it direct current. E11 some instances it is desirable to employ alternating current for operating: the 'llnu'tions: but when it is attempted to use su h alternating current For operating purposes, it has heretol'ore been found liliicult to retain the dynamic indication principle. partly because the cross protection relays and other safety devices employed in the direct current system would not be adequate tor an alternating current system, and also because of the tact that alternating current IllU'tOlH. as ordinarily con structcd. cannot be relied upon to generate an indication current dynamically after each operation.

My invention ontemplates the provision of suitable and adequa e safety devices l'or alternating current electric interlockiin systene-g employing: the dynamic indication principle. so that by using; a motor capable of reliably generating an indication current dynamically; a safe. ellicient and reliable system o 1' electric ll'llPIlOt'killg" can be produced.

tipcciiically considered one ol" the objects of my invention is to devise a simple reliab e and adequate cross-protection device for alternating current systems which will act to prevent improper operation or wrong manipulation of the system on account of Serial No. 277,267.

crosses, or other improper electrical conditions, between the operating wires of the same or rlitt'erent functions.

A still further object of the invention is a simple and reliable indication mechanism For alternating current electric interlocking systems which will serve to protect the system against false indication, by reason of tlw Fact that such indication mechanism is respon ive solely and only to the direct current used for indication purposes and is not att'ccted by any alternating current finding its any tor any reason through the indication mechanism of a function at any time.

Other objects and advantages of my inmotion will appear as the description pro oresees, ol the particular embodiment of my invention selected to illustrate its functions and characteristic features; and the novel Feat res ot my invention will be pointed out in the appended claims.

in describing: the invention in detail, retcrence will be made to the accompanying d awings in which is illustrated one prer'erred physical embodiment of the invention. in which like reference characters desi nate corresponding parts in the several i' ews. and in which:

Figure l is :1 diagrammatic view. in the nature of a wiring diag am. showing the parts at an electric interlocking system embodying the invention. together with the clectrieai connection between several parts;

Fig. 2 is a diagrammatic view of the motor which is preferably employed in my system o't interlocking;

Fig. 3 is a partial transverse section of one (it the circuit crnitrollers on the switch machine showing more in detail the form and relative arrangement of the conta t pieces, together with the contact springs which cooperate therewith: and

Fin? 1 is a diagrammatic view, partly in perspective with certain parts broken away and spread apart tor clearness. showing in a simplified Form the significant features of construction of the switch machine or switch operating: nuchanism which T preferably employ in my system.

f'lcvcral ot' the parts and devices of the interlocking system embodying my invention have been employed in a direct current system. and since such devices are Well known in the art. I have shown them in a simplified lornl. more with a \ien ol' mak in; it, easy to understand the eonstruetion and mode of operation of my invention, than to show the exaet ronstruetion and arrangement of parts whieh would be employed in u eommereial system.

In the usual elertrie interloelrin g system. earh switrlu sitrnal or other 'l'unrtion eontrolled hy the interlocking niarhii'ie. is gorerued h the manual manipulation ot a slidalile. liar ll, ronunonly termed a lever. whieh is provided with a suitahle handle (3 tor t'arilitating its manual movement. In the areonlpanying drawing only one lever TA and its associated parts are shown. but it is to he. understood that there are several sueh levers ordinarily included in each interlorkingmaehinm and that earh lever and its as soeiated parts constitute a unit suitahle tor eontrolling one o! the :nvitrhe; signals or other l'unetimis. The ditl erent levers :1 of an interloelrine' marhine are arranged so as to he eontrolled h any suitable loriu ot' nu-rhanieal inlet-lurking; whirl: lit-in;- well known in the art has not heen illustrated: and this Inerhanieal interloelzing is actuated h eaeh lever L hr means of a linlt T. the upper end of which is prorided with a roller engaging a ram slot R in the lever L. whereby the movement o the lever Ti mus s a movement of the linl; i' and the parts oi' the nleehanieal interlocking; ronnerted thereto.

The lever Ii is supported in a suitable guide 9. and on this guide is pivoted a lateh to whieh is arranged so that when one and is raised against the opposition of a spring: 11. that end will eooperate with rertaiu shoulders formed in the lowrr ealgie ol the lever L so as to limit the movement ot' said lever in rertain positions. .lso pivoted lo the guide ll is an angle lever lorln ue' :1 don or latrh 1:2, whirh is arranged to (lllt'll under the adjarent end ol' the latrh l! and hold said lateh in its upper lurking position: and also pivoted to the guide 9 is a emu oi tiuuhler l3 whirh is. arranged so as to mutualthe dog 1; and swing it into position to hold the ateh l!) in its loeked position. the tumhler 1 heing urged toward the position shown in the drawing lrv a spring it and being provided with upstanding teeth whirh are arranged to he engaged in ahntnients or shoulders torlned along the l wer edge oi the lever it to move said tnnihler t l to swin; the dog l2 into it lorliing position. The ring 1:. is arranged to he tripped in :1 HM 5 attaehed to the armature ll ol' the iudiratio-n nieehanism t.

This indieation meehanisin l is so eonstrueted and ar'anged that it will operate on direet. current hut. will not operate on alternating" eurrent. The particular form of the indication mechanism shown eonr urises two eleetro-lnag'nets arranged ahove and lltl( the armature to. earh eoil ol the upper (llfitti'ti-Hlllglltt heinn' provided with two windings ll and t5 supported on the same eorr or pole pieres so as to he in indurtire relation to eaeli other. and earh eoil ot the lower elertroanap'net havinga single winding 19. the terminals of whirh are eonneeted hy low resistanee ronduetors it] to the terminals of the winding in of the upper eleetro-magnet. Normally the armature l6 ol' the indication nierhanisni l rests on the pole pieees of the lower eleetro-inagnet hot is raised when direet. eurrent llows through the winding: 17 ot the upper eleetro-magrnet in the usual way, so as to trip the dog 12. ll hen the winding 17 ot' the upper eleetromagnet is energized by alternating, current howeren similar alternatingeurrent is in- (hired in the windingis of this elertro4l1agnet as will he elearly underst od li those skilled in the art, and this indured eurrent; also flows through the winding; ll) ol the lower elm-lroana fnet: and sinre the mug netir llnx generated h the eurrent indueed in the winding; L8 is opposite to the flux generated by the alteri'mting current flowing in the winding 17. and sinre the flux grenerated in the indured current flowing in the winding 19 of the lower eleetro-niagnet predominates in its, pull upon the armature lt due to the tart that this armature rests on the pole pieres o! the lower ele trounagnel. while there is a eonsiderahle air gap hetweeu said armature and the pole pierrs ot the upper eleetjro-ma net it is apparent that the armature 16 will not he attrarted upward and will not operate to trip the d g if.

The lever l; governs the rorrespondiuei l'unrtion lrv routrollinn rerlait: elertriial rirruits. and tor this purpose a rod it is eonneeted to the level" It. and serured to said rod are two metallir eontzu't l lor'lis i2 and 2? insulated from earh other and arrangel to eooperate with pairs ol rontnrt springs .Bl. 25 it; and .ET.

The lever l. has i'our iie nitirant positions. namely; first its innermost; position (shown in the d awiug'i whirl: position is ooted ieutly termed the normal position, seeond. the position in whirh the lever is pulled to its outermost exlrrinm whirl) position is wonrenilnt lv termed the reierse position: thirih a position near the inner or normal position in .Hhivh the rontart idorls I"! and id iuuhe rniitrirl with the rorrespou:lina pairs oi on a t pi'iit Hi and tfi llllt in whirh the rod 7 has not tori-ed down li tlu l'l ll slo to its lowermost positiozn this posit on f th-r lever hein g eonvenientlr termed the nor moi iodiralion position: and tourtlu a posi tion near the outer or rm'erse position in whieh the rontaet lilorks t3! and 2 make eontaet with the eorreupondinp; p irs of eontaet springs Q and Elk, hut in whirh the rod T has not he n raiee l to its up 'urin st posil ill l ill] lilt) Zill dil

tion. this latter position of the lever being conveniently termed the reverse indication position.

For a clear understandin; of the operation and features of this invention a further detail description of the construction of the lever and the parts associated therewith is not deemed necessary; and if desirable a fur ther descril'ition of the construction and operation of these parts may be had by referrin; to the patent to John D. Taylor. TSEZJQT. February 16. 1904;.

Supported in an v convenient manner adjacent to the lever l, is an indication selector comprising two clcctroinagnets 28 and 29 hctwccn which and arranged to be attracted thereby is an a rinaturc or contact bar 30. said contact barlllJ being; in contact with a contact spring 531 at all times and with contact i-prinn's 32 and 213 respectively in the two cxtreincs of its movement. Other features of the construction and operation of the indication selector are described in the patent to \V. K. Howe. 1.163.154. Dec. 7. 1915.

The protective device for preventing an improper operation of an interlocking: system by a cross between operating: wires or the like. is shown as comprising an alternating current rcla v R. which is prefe 'ablv of the tvpe commonly known in the art as a single clement relay. that is. an alternating current rela v havin': a single phase field. such as a relay of the well known vane type or one provided wit] a rotor and pole pieces having: shading" coils. The relay it is arranged to operate three contact lingers or armatures 1H. 35 and 36 which are shown conventionally in the drawing. Thcre is also associlteii with the rclav ll a manually oi'ierable switch K for the purpose hereinafter explaincd.

The parts of the electric interlocking tern so far described are located in .the tower or cabin. adjacent to which there is also located a suitable source of alternating current. as a transformer T. the printer of which is connected to a suitable source of alternating currcnt: as a generator. and the secondary of which is connected by suitable conductors hereinafter pointed out in detail. which constitute the o 'ierating and control circuits of the function. This invention is shown applied to that part of an interlockinn svstein used for operating a switch; and the parts of the interlocking! system which are located at the switch are shown enclosed in a dotted rectangle designated The apparatus for unlocking. inovinc and locking? the switch points of the switch. may be of any suitable or well known construcion. but l prefer to use the switch machine shown and described in the patent to W. K. Howe. No. 1.289.595. Dec. 24. 191 In Fig. -l l have shown in a simplified and (liaejranr amtic war the more essential and important parts of this switch machine, together with their application to a col'ivcntional switch. Referring to Fig. 4. the stock rails of the conventional single switch shown, are designated 3H. and the movable switch points 35. 'lheseswitch points 35 are connected in the usual way to a throw bar 36, and a lock rod 3T. these parts being separated and shown to dilferent scales for convenience and clearness. The throw bar 36 is moved back and forth by the operation of the machine. as hereinafter explained. to shift the switch points from the normal position. shown in Fig. 4. to the reverse position. and vice versa. The lock rod 37 is locked at the switch niachine. as hereinafter explained. and serves to hold the switch points 35 in their normal or reverse position. The parts of the switch machine are operated by an electric motor M. prcferabl constrllcted as herein-a fter explained. The armature A of this motor drives a bevel pinion 38 through a friction clutch 39 of an; suitable construction, such illustrated in the Patent 1.288.595 above noted. The bevel pinion 3S drives a beveled gear 40. and this gear in turn drives a. shaft 41. to which is fixed a pinion 42 meshing: with a main driving near 4.3 jonrnaled upon a fixed stud 44. hastened to the main gear 43 is a downwardly extending driving pin or stud 45 which carries at its lower end two freely revoluble rollers 46 and 47. The driving: pin 45 travels in a circular path. indicated by the dash line 48. as the main gear 4.3 revolve. The throw bar 36 is formed with a laterally openiing jaw 49 shaped to receive the upper roller -16 of the main driving pin 45 as said roller travels in a circular path. in such a way that the throw bar is moved back and forth as the main gear 43 makes approximatel one revolution first in one direction and then in the other. Extending lengthwise of the machine and supported by suitable guides. is a slidable bar or locking plunger 50. This locking plunger 50 is provided with an enlarged head at one end in which is formed a cam-shaped opening: 51. of a general elliptical shape. the roll r l? on the driving pin 45 being: disposed to cooperate with the faces of this cam shaped opening: 51. Fastencd to the locking; plunger 50 is a lock dog 52 adapted to pass behind shoulders formed on the throw bar 36. so as to lock this throw bar against move ment in one direction. In F g. 4. the locl ing dog is shown as locking the throw bar 36 in the normal position of the switch points: and after the switch points ha e been operated to the reverse position. this locking dog: moves behind the opposite shoulder on said throw bar and locks it in the reverse position. Near the other end oi the locking plunger 50 is another lock do; 53 (which for convenience is shown a broken into two parts). This loci: dog 53 ill] thow designatml it adapted to enter normal and, i'ererse nut hes 54 and in the ltl('l( rod ST. in Fig. l the lork dog: 53 illu:-trated as heinr in the normal notch 54. so as to hold the loci: oll 37 against endwise morei'nent in either ilirertion: and when the switch points are operated to the rover-1e position and again l rheil n). the loci; do;- 5 enters the reverse notrh in the look rod 37 and looks the lt'.ll points in their reverse position.

lhe motor operating rireuits and the iudiration rirruits are opened and closed solertively in arrorilanre with the. movement; of the parts of the switch niarhine hy a nilruit eontrolier. ronunonly termed a pole rhang'er. whirh illus rated in a. simplified term in Fig. i as romprisingi' a eomart lilorl-t or panel fit; of suitahle insulating: material. This rontaet hlorl; it) is supported to slidh riz ntally h being rarrie l hi the orez .IT-Jfi" of two opposing: pairs ot' solenoids 3H and fit), these rores lining slidahle in the sol noid. Fastened to the rontaet hioek 5 3 are two inetzillir r'ontart or hridging: pieces on and ti which are arraluz'ed to rontaet with pairs oi contact springs (32 to (i? with the cont-art liloel; 5G in one extreme or normal po itioin as Sl'HHVIL and with similar ontart s n-lugs 66 to when said contact l lot'lc is shifted to its other extreme or re verse position. The rontart, hlorlr .36 is shifted hark and forth nimrhanirally h an arm To, one end of whirh is notehed to straddle a pin 71 serured. to said block 56. The arm T0 is journaled loosely upon a. haft T2 and is provided with laterally extending wings or lugs T l. (Only one 05' these lugs TI) appears in i i l. the other wring hidden h other part hut the shape of these lugs is suhstantially the same as 81 and 81 which are cl arly shown.)

The rwitrh nmehine infllules another virt'l lt ontroller whirh. in the simplified form illustrated. rompriees a hloi-lq tlol suit-aide insulatin material guided to more hori- :mntall irom the normal. position shown to an opposite reverse position. similar to the movements of the Contact hlork I 6. This other eontart llltltk T-l rarries two (-ont'art nieres T and T6. The eontaet piece T 1 makes rontavt with a pair o't rontart spring IT when the vontart lilorlq Tl is in the nor mal pori itii'ui: and the militant piere To ow tarwith a, similar pair of rontart springs in in the reverse position ot' said lilorh. t ontart lilork it is iuored haul; and forth hr an arm 79. the outer end of which is formed with a slide to reeeire a pin attarhetl to said eontart hloelc. The huh of the arm T9 is fastened to the shaft 72 by a pin or other suitable means. and. integral with said huh are two laterally extending;- lugs 81. Bl, these log; heingg' the same shape as the lug); T? of the arm ill and being disposed direetly over the latter lugs. To the lower end ol the shaft T2 is fastened a laterall extending: toot or arm h ll. the en P'H'tlflll :it' which is formed with flaring edges. hastened to the locking 'ilung'er it) are two guide liars $53 which are spared apart for the greater part of their length a distance equal to the width of the head of the arm #42. These guide bars 83 are hereled off at one end, so as to flare apart. and these beveled ends are shaped to cooperate with the flared edges oi. the arm 82. in slu'h a way that sliding movement of the loelting plunger 50 {to the right as viewed in Fig. 4) arts to shift the arm 9:5 to its central position, t or the purpose hereinatter explained.

.lournaled in suitalile supports (not shown} ahove the lock rod 37 and extending transversely thereof, is a shaft 85 to which is fixed a rocker 86. hloek HT is fastened to the upper edge oi the look rod 37 and is adapted to raise one end of the rot-her Ht; aerording, to the position of said loelr rod. A tripper arm is pirotally (mnneeteii at its upper end to the shaft 85 on a pin 89 so that this tripper arm may swing back and forth lengthwise of the machine. while living: swung crosswise of the machine to opposite sides ot the shaft 72 by a rorrespondinq rocking movement of the shaft 35. The lower end of the tripper arm 8h is provided with a. lug" 90 adapted to engage those wings 81 and T3 of the levers T9 and. 70 respectively whirh are on the eorresponding side of the shaft 752: and said tripper arm is also provided with an ewtensien 91 adapted to he engaged h the look Will 5%.

Detail .leatnres oi the ronstrurtion and operation of the switch machine referred to are desrrihed n the Patent M28859?) ahore mentioned: and I will explain only hrietl the operation of th s snit'rh inaehine. The parts are shown in the normal postiou in Fig. 4. hen the motor is snp 'llied with ope "ating Current. as hereinafter explained. with a View oi moving: the switr-h points to the reverse position. the main gear 43 and the driving pin 4:5 are rotated in a. ('onnt'errlookwise position as v ewed in l igz. t. The roller 4-7 engages the ram l'are 51 and moves the inviting plunger Ml endwise (to the right as v ewed in l igg. t). This moves the lorh ing Iii! out ol lurking engnnrenwent with. the throw har Il and like 0 the ot-l d-sig o l out of the normal notrh fi l of the lfltli rod 31 thereby treeinn said throw iar and ltith rod to permit the switrh points to he shittml. During this movement of the looking: plunger 50 the foot 82 is swung: to the middle position, and the arm 79 hein g fastened to the shaft '72, is swung to bring .he rontaet hlorlt '11 to the middle position. This tion does not concern the ordinary operation of the machine, but results in making it lltl possible to reverse the switch points in midstroko. as explained more fully hereinafter. It, should be noted that the arm Til. being loose on the shaft TL. remains in the. normal position shown. As the lock don; oil is withdrawn. the trippcr :zrm sh swings bark by its own weight and hangs rert cally. After the unlocking oi the switch points. produced by the cooperation of the roller 47 with the am taco fil g'has occurred. the roller it) enters the jaw 49 and moves the throw bar 36 to shift the switch points 35 to the reverse position. The lock rod 37 follows the movement oi the switch points and asauincs its reverse postion. in which the block FT engages the opposite end ot the rocker an and swings the trippcr RH to the opposite side of the shalt T2. Also. the reverse notch in the lock rod 37 is brought opposite the look dog 53. After the movement oi the throw bar is completed. the roller- 46 leaves the jaw 49. and shortly thereafter the roller 4-7 engages the cam face 51. and returns the locking plunger :30 to re-lock the machine. Upon the final movement of this locking plunger Til) the lock dog .33 engages the extension EH on the tnpper arm and since this tripprr arm is now on the opposite side oi the shaft 72 from that shown. said trip per arm engages the wings Hi and T3 (not shown) resulting in shifting contact blui'lis 5b and T l to the opposite extreme. or reverse position. The movement of the contact block 56 results in the interruption oi the operating circuits supplying current to the motor and the establishing of the indication circuits. as here naftcr explained. The niotor. being now acting as a generator. is gradually slowed donn or smiblard. so that the main gear 43 and the driving pin -15 come to rest approximately in the position shown. The indicat'on current generated dynamically by the motor is trans niittod to the tower and serves to operate the indication mechanism. thereby signilying' that the switch points have been properly moved and locked. The sequence of operat on and movement of the parts in shifting the switch from the reverse posiiion to the normal position is similar to the operation already des'ril'icd and will be readily understood without dcta l explanulion.

The motor M for operating the switch machine may be of any suitable construction. providing it will operate efiiciently on alternating current. pr ferably with ser es charactiristics. and w ll also act to generate a direct urrent dynamically without fail when the operating current is cut oii and its armature and tiehl are connected into the indicat'on circuit. The motor 1- pre'l'er to use is one having the teatures oi" construction shown and described in the application of James Burke. Serial No. 147.325. tiled l ebruary 8. 19W. now Patent No. LSULLHH. l ebruary l. 1921. In l igurc 2 ol the accompanring drawings l hare shown dia' ranunatically the s gnificant features of iainstruction ol this motor. incluilim: the hold structure and tield winding. licferring to Figure. l. the field winding or stator ot' the motor is divided into four sect ons H5. 9:3. 95 and ha each section being made up of laminar ol' the shape shown. with teeth 96 (three being shown) at each end of the section with a comparatively large intervening opening 97. 'l'hesc lam Inc are built up to produce a stator ot' the requisite thickness; but instead oi using laminae oi uniform magnetic oharactoristics. some ot the laminae are preferably made of a harder steel. or a steel of different composition. or a matcral. otherwise ditl'erinp; maimetically from the material used in the remaining laminae. The proportion of the hardened laminae may be varied and it is found that good results are obtained when the laminar consiitote about one-tenth to one-filth of the total stator laminae. Each stator section an to 9:3 is spaced from the adjoining sections. as shown in Figure 2. about the width of a slot l'iotween the teeth 913: and each section is cut away at its corners as indicated by the numeral Ell) so as to reduce the magnetic conductivity between adjoining sections. The tour stator sections 95 to 95 are sutably supported in a frame or housing .38. preferably of some nonanagnetic material. like brass.

The tour licld poles are formed by the teeth 9t) ot the two end portions of adjoining}; stator sections. The field winding. nhich is a distributed winding, is illustrated as made up of three coils per pole. the numlicr of turns per coil being a suitable number. and oi" course. much more than the two turns which have been shown tor convenience. Tracing the field winding and starting at the upper left-hand pole. the turns of the outer coil itlti which embraces the three teeth 5H3 ot the stator section 95 and the three teeth iii, oi the stator section 97 This coil 100 is connected in series with the next ooil llll which embraces two teeth ot each of said sections; and this coil in turn is conncctcd in series with the inner coil to. cmbracing only one tooth of said adjoining section. The terminal ot the inner coil In) is connected by conductor 103 to the outer coil Hit-1 of the winding for the next righthand field pole this coil 100 embracing three teeth of each oi the adjacent sections 5);?" and 9:3. the same as in the case of the coil Hit The coil W0 is connected. in ci'ics to coils 101* and 102 in the same way prcvi ously described. these coils. however. being: wound rerersely to those oi the winding for the other pole so as to g ve the neces axry polarity. The windings for the remaining Lit] poles are the same, snveessire poies heingg ot' UilflJa-litt polarity. 'lhe livid rolls are (121% nec'ted in multiple in pairs, the (oils for the two upper tiehl poles shown in Fig. 7: heing rennet-ted in series with earxh other and in multiple with the (oils for the two lower field poles. whieh in turn are rronneeted in series with earl! other. The two upper and lower pairs of tield coils are made ol' different impedanee. Asshowina nondndnetire lt: istanee 101- is eonueeted in series with the \\'intliln -'s of the upper lield poles, and an iijnluetire resistanie 105 in series with the 'lfliilfififi oi the lower tiell poles. result, the currents in the upper and lower windings are out ol phase with eaeh other, tor the purpose hereinafter explained. arious means may he unployed for ohta uin;- this phase displaeement. as will he readih understood hr those skilled in the art. A ditl'erenee in phase of ahout ten electrical degrees has heen found to produue good results.

The stator is provided with eompensatint! windings. eomprising short eireuited coils of \'(I'.\ low resistanee located in the end slots of each section 9.3 to 9:3. For example. in the slot nearest one end of the seetion 9.7 is a eonduetor lot and in the eorrespozuling slot at the other end of said section is another t'UIitittttUl' toil; and these two eontluetors are :onueeteti by end eonniwtions. as iudieatei'l diagrannnaticall the turns having very low resistance and being in bar or plate town it desired. Flimilarly, a elosed eoil 10? is located in the other slots of the section 95*. in the central s ieee S)? of eaeh seetion a plate 1% of lo resistance pret erahly provided with hent up end portions for eoi'lveniently holding: the plate in posi tion.

The armature of the motor is made up of laminae having teeth 109, prele 'ahlv hearing; an im-ommensnrate relation to the nuniher of teeth of the liehl poles. The armature winding may he ol any suitahle form oapatale of giving the desired perl'ormanee in an alternating eurrent series motor: l

and lo; Simplieity this winding has not heen sir-own. The motor is provided with the usual cone mntator designated 9:5. and with suitahle hrushes which are tie. gnated Z and .7).

The particular features ot' the motor adapting it for use in an alternating eurrent electrie interhuzking system reside in the 0X- pedients employed to preserve an appreciahle amount of residual magnetism in the magnetic circuits of the stator, so as to positively insure the building up of a niagnetie Held when the motor is eonneeted. into the indication circuit and arts as a generator. The use of laminae o'l' dillerent magnetic characteristics in the stator results in the orele of magnetization of some of the laminae heing delayed or lagging behind the eyrle in the other iannne; and the lamiuze o'l' difierent magnetic rharaeterisths r-lh'l1 as solt and hardened. helng subjected to the same 11121;} unto-motive i'oree. certain of the lamina will always, it is found. in praetire retain an appreelahle amount oi' residual magnetism, regardless of the partieular instant or portion of the eyele the alternating rurrent is out till. Also, with the tiehl windings (5onnei-tecl in multiple as deserihed, and the magnetiicingg eurrent in those \$-:iu=;lin; s heing out of phase tlll' eouditions are slurh that, regardless oi' the instant when the alternatine i'lll'ielll lrinterrupted. there will always he an ;E },.-i;EGt7 13i!lt eurrent passing 'hroup h at least some ol' the livid win-line's at the instant oli iiiteirupi ion. therehy resulting: in some ot' the poles heingr leit with an appreriahle amount oi magnetism. it will he noted that the stator construction is such that the flux paths or magnetic ci cuit tor the fin): rreated by the currents (littering in phase. are segregated so as to obviate the possibility oi neu tralizii'ig action ol' the eurrents oi different phar'se. Actual use of this motor has demonstrated that there will always he snilioient residual magnetism in the stator to permit the motor to operate as a generator, and piek up and selt-exeite its hold so as to supply a direct eurrent which may he used for indietion purposes. in an mini-looking system the momentum of the armature o the mo tor. after the operation ot the function has heen completed, supplies the energy for generating the indication current. The act of generating this iinlieatiou alr: results in liltlltillg or S'Hil'illlltf the armature of the motor. so as to tiring it easily to a stop without short: and ar.

Upe 'ation: in order to ohtain a dear understanding of the tuuetions performed by the cross-protei-tiou relay, under the almorinal eonditions produred hy a cross. and also the features oi safety ohtainol h the use oi the indication nieehanisin shown and described, it is expedient to consider first the operation ot' the spatem under normal and ordinary working: vonditions, and l will lirst deserihe hrietiy the operation of the system and the various rirruits estahlirhed in moving the :-.-.\'itrh from its normal position to its reverse position, Referring to Figure l, the parts: are illustrated in the positions (:orresponding to the normal position oi' the switch. and. to more the switeh to its reverse position, the iever ii, is pulled out to the lett. as viewed in Figure l. to its reverse indiew tion position. to which it may he moved without (mposition. prorid id the merhaniezl looking permits. The lever l), however rannot he moved leyond this point on aeeonnt of the action of the indieat ion latch 20. In the reverse indication position the eontaet liloelqs and 3 IlltP-ix't" c nt-art with the pairs of rontar't spring 2 and :25. W'ith the ron tact blocks in this position. current will be supplied from the transformer T for operating the motor of the switch machine along a circuit which may he traced as follows: commencing at the upper terminal of the secondary of the transformer T. conductors 110 and 111. magnet 28 of the indication selector. conductor 112. contact springs 24 and contact block conductors 113 and 1H. contact spring (3:2, contact piece (3H. contact spring (33. coiuluctor 115. armature A of the motor. conductor 116. contact spring (14. contact piece (31. contact spring (35. conductor 117 through the field of the motor. common return wire 118. armature 36 of the relay R. conductor 1 l9. switch K, comluctors 120 and E21 hack to the other terminal of said secondary. The normal pole changer operating coils 5!) are also energized at this time or current flowing in a hranch circuit which ma he traced as follows: commencing at the contact spring (32. conductor 122. coils 59. conductor 123. contact springs 77, contact piece 75. conductor 124 to the common return wire 118. The cnergizatit'm of these pole changer coils 59 at this time merely serves to maintain the contact hloclt no in its normal existing position.

(urrent flowing in the reverse operating circuit, just traced energizes the magnet as of the indication selector and moves the contact liar 30 from the position shown to its other extreme position. read to establish the indication circuit. The detail signiih -ance of this operation forms no part of the present invention and is explained more fully in the patent to V. K. Howe. 1.163.154. mentioned above. The reverse o 'ieratingcircuit also supplies current to the motor at the switch and causes this motor to unlock the switch points. move them to the reverse position. and then lock them again. all as previously explained in describing the operation of the switch machine shown in Figure 4. As soon as the switch points are shifted to the reverse position and locked up, the contact block 56 is shifted from the position shown to its opposite extreme position. therehy interrupting the reverse op erating circuit and establishing the reverse indication circuit. this latter circuit heing traced as follows: commencing at the armature A. of the motor. conductors 11(3 and 125, contact spring (57. contact piece (it) (now shifted into contact therewith) contact spring (36. conductors 126 and 127. contact springs and contact l)lfi('l{ 23 (the lever l1 being in the reverse indication position).

conductor 128. contact spring 32. contact arm (this arm having been previously shifted by magnet 28). contact spring 31. conductor 129. winding 17 of the indication mechanism. conductor 1 F10. armature of the relay R. conductors 1.231 and 1232. relay R. condurtort 133 and 120. switch K. conductor 119. armature a of the relay R. conductor 118 through the field of the motor. conductors 117 and 134. contact spring (39. contact piece (31. contact spring (3H. conductors 135 and 115 hack to the armature.

The armature of the motor continues to rotate due to its acquired momentum. and when the indication circuit just traced is estalilished. the motor connected into a closed circuit and is in condition to act as a generator. it heing noted that the armature and field of the motor are relatively rcversed in the indication circuit opposite to their connection in the operating circuit. so that the small current generated in the armature by the residual magnetism of the stator flows through the windings of the stator in the right direction to build up this magnet ism. The indication current thus generated. although of limited duration. energizes the winding 17 of the indication mechanism sufficiently to raise the armature 11'. trips the dog 12. and releases the latch 10. therclrv permitting the lever l) to he pulled to its full reverse position. The movement of the lever L to its full reverse position does not alter the circuits set up at the time. and the function and the lever are now at rest with the iiulication circuit last traced intact. it should he ohscrved that the indication cur rent, being direct current. does not affect the relay R. nor cause the windings 1b and 19 of the indication mechanism to interfere with the movement of the armature 16.

It should he noted that in the arrangement shown in Figs. 1 and t. the pole changer coils 58 are connected in multiple with the field and armature of the motor. at the time the indication current is generated. the conduct ing path constituting this multiple connection heing traced as follows: commencing at the armature A of the motor. conductors 115 and 135. contact springs 68 and (it). and contact piece (31. conductors 134- and 11?. held of the motor. conductors 12+ and 1%. contact springs 78. contact piece T6. conductor 137. coils 58. conductor 1 3 contact spring-z 66-6? and contact piece (if). conductors 125 and 1 to hack to the armature. in practice. the pole changer coils 5n and 59 are of mmparatively high impedance to alternating current. hut are of comparatively low ohmic resistance. lt is found that thisconum atively low resistance path around the armature and field of the motor at the time it is huildingup its field flux to generate indication current serves to improve the performance of the motor in generating indication current. especially where the function is located at a considerahle distance from the tower so that the line resistance is connnn'atively high. I do not attempt to explain the theory of this operation; and while the motor will generate indication current satisfactorily with the pole changer coils in multiple therewith in til) many instant-cu. in other inatauces it appears to he desirable to exclude these poie changer coils at the instant when the motor is building up the indication current. in the latter inatances. I employ the constriu'- tion of contact apriuu's Ti and TH and contact pieces T5 and To illustrated in Figure 3. in this construction. it will he noted that the contact pieces T5 or Tl: do not matte contact with their cin'respondiug pail ol' contact springs: TT or Te when the contact lblUt'li T 5 in the extreme normal or rercrsie. position. When. hmvever. as previously explained. the switch machine commences to unlock. the contact hlocl; Tl is moved to the middle po rition. in uhich both pairs, of contact spring-e Ti and It are bridged by their correspending contact pieces To.

The operation of moving the switch points from their reverse position to their normal position involves analogous more ments and circuits and need not lie descrillet'l a detail.

The pole changer coils 5n and 59 are eInloyed to permit the switch points to he reversed il' occasion requires. For example. wine ohstiuction. as a piece of coal. may iirercnt the switch points being fully thrown at the first attempt; and it is desirable that the towerman he able to restore the partially thrown switch to its former position. The tou'eriuun returns the switch to its former position. utter it is partly thrown. by merely moving; his lever ll hack to its former position. For example. it an attempt has been tirade to throw the switch to the reverse position. the lever L is returned to the normal indication position; and since the ewitch partially thrown. the pairs of contact springs T7 and T3 are hoth bridged hy the cuntttt't pieces T5 and T6. and with the lever ll in the normal indication position. current is supplied to the pole changer coils on. current being cut oil of the opposing coils 39. .\s a result. the contact hlocl: 56. lwllti ree to mov hmrause the switch mahine has partially operated. is attracted lo, the coils 23H to its opposite extreme poeilion. whereuipon the operating circuit for restoring: the switch machine to its normal position is eetahlished. hen the switch it returned to its normal position. the towerman gets an indication and then trys again.

With this hriet description of the operation of the system under the usual and normal working. conditions, it is now possible to explain the function performed by the protective relay B when abnormal conditions due to a cross or the like exist. One example would serve to illustrate the protection afforded by the relay R; and for a simple illustration. assume that a cross. as indicated at 200. is improperly made between the two control wires. this improper mnneetion heing due to the lueakin c down ol the insulation of these wires. or any other cause which results in a conducting path lltlllffl' established hetwecn said wires. Vith .-uch a cross zllll'l. and with the parts in their normal poaition. it can he seen that unless some special protection is afforded. the switch machine may he operated. to move the switch to the reverse position. although the lever ll still remains in its normal position. To illustrate. disregarding for the moment the action of the protective relay R1 current may flow from the sccondaur of the transformer T out to the motor oi the switch machine hy reason of the existence oi a circuit which may he traced as iollowa: comuiencing at one terminal of the secondary ol' the transformer T. conductors 110 and i735). selector magnet 29. conductor 140. contact springs 2b and the contact lJlOt'k 22. conductor til. thence along: conductors 126 to the point. where the cross 200 occurs. thence through said cross connection to conductor ill. and thence out to the suvitch machine and through the motor along: the same path heretofore pointed out in cxpiaining the operation 01' moving the switch trom the normai position to the reverse position. it current were supplied to the motor in this way it would cause operation ol the switch machine. and this would result in placing the switch points in the reverse position while the lever T1 remains in the normal condition-somethint: which cannot he tolerated in an interlocking system where sat ety requires that a function should always he in ciact correspondence with its controlling lever. The dangerous condition just desicrihed is obviated hy the action oi the protective relay R. At the point where the improper cross 200 exists. current may flow hack along the control wire 1H. as well as out to the motor at the switch machine. the path for such current being traced as tol lows: commencing at the cross 200. control wire 1H. comluctor 142. contact. springs QT and contact hlock Q3. conductor ill). contacts ilis illh-iil of the indication selector. coirdoctor 113$ rolls 1? ol' the indication nil-clue uisin. conductor 13. armature I ol' the re lay l). cmuluclors l3] and 132. windings: of the relay R and condur'rtors 132i and 121 hack to the other terminal of the transiorn' er T. This last traced path through the indication mechanism and the relay R ot comparatively low resistance so that a large proportion of this current passes through the relay R, The current in question in alternating current. being supplied irom the transformer T. and thin alternating current operates the relay R and causes it to attract its armature or other movable element and raise the contact fingers or armatures 34. and 36 shown in Figure 1. The raising of the armature 36 interrupts the connection from the common return wire Hll ill)

118 to the transformer T. thereby interrupting the lion ot current through the motor at the switch machine and preventing: operation thereof. The raising of the armature 3a interrupts the branch circuit; through the indication mechanism 1. thereby econ mizinp in current preventing the overheating of the coils oi indication mechanism. and obviating: any other dithcu'ities which might result from the con-- tinucil flow of current through said indication mechanism. The raising! of the armature 34 of the relay ll establishes a stick circuit for i'nainiainilur said relay R energized indepeni'lently oi the branch cir cuit through the indication mechanism. said stick circuit being traced as follows: commencin :u the lower terminal of the transformer T. conductors 121 and 133, relay ll. .onductors 32 and 1 H. armature 34. conductor 14 5. switch K and conductor H6. pretl erably to an intermediate tap in s-. id secondary. this intermediate lap being used. so that the current applied to the relay R is not, strong cnough to iniurc or heat the windings of the relay. clthoun'h continued for some time.

From the foregoing it will be evident that the relay R operates instantly to automatically disconnect the motor of the switch machine from the transformer T. in case an improper connection. such as the cross 200. is established between the two control wires iii and lQo. Further. the relay B. having once heen initially operated. is maintained energized, hy reason of its stick circuit. until manually restored. Tlu manual restoration oi" the relay it is accomplished by opening the switch K. This interrupts the stick circuit and permits the armature of said relay to return to the normal position in rcspoi'isc to the bias provided in such relays 'l hc opening of th switch I; also interrupts the comic tion from ci'inductor l 19 and 120. so as to open another break in the common return connection from the switch machine to the transformer hi. onscipicntly. although the armature h; oi the relay falls back to its normal position. there is no current supplicd to the motor of the switch machine. though the cross Qflfinmy still exist. Before the function in question can be operated the switch h. must be re closcd, it the cross still exists. the relay ll is again innncdiatcly energized. and with the switch K closed. the relay it is again maintained energized. In this "way. so long as the ross '30.) exists the common return connection from thc motor to the source of current cannot he permanently established. and no attempts of the operator to use this function are effective until the cross has been dotcotcd and removed.

It will he observed that when the function is at rest. there a closed circuit including the relay R. the indication mechanism 1, and the motor. th s closed circuit being the the indication circuit last used. ilso. this circuit i connected to one teriuinai (It ihc tiansiormer (this connection wing conductor 121 in Fig. 1). Consequently. improper supply of current to the rotor. tending to operate it falsely, must nc 'cssnrily have a hrunch path through the protective rchiy ll. regardless of how this tili llfipiil supply of current is obtained, 'ihus. the system is protected against cnosses other than the one indicated at 200, as for riuniphg when the operating wire of one tuneon connected to the source of current is rossed up with the operating wire of another fun tion. all as will he clearly understood h those skilled in the It is also characteristic of this system that the relay R is included in the indication cirvuits. so that tlu integrity of the winding of this relay is checked at each operatiim of the function. Obviously. various modifications and amplifications of the principle of cross protection shown and described may he made Without departing from the invention. I prefer to use a vanetype signal element relay for the protective relay R; but obviously other electro-magrnetic devices could he used for the Same pur pose. providing they Will respond to alter nating current but not to direct current. In the cmbodiuu-nt of the invention illustrated. the protective relay R has been shown as arranged to interrupt the common return conncction of the particular function affected; but obviously. the practice sometimes employed of having the cross protection relay act to interrupt a common return connection for several functions. may be used if desired.

The indication mechanism 1. as previously explaincd. is constructed so as to be responsive to diroi-t current. but not to alternating current. This is done in orocr to obviate any possibility of obtaining a false indication from a source of alternating? current used for operating the functions. reggardlcss oi' lion." this alternating current may find its Way through the indication Incclr anism. This feature of my invention is important because the various combinations of crosses and other conditions which may occur in practice are very numerous. and in some instances it is possible for the altcrnating: current to find its Way thi oup h the indication mechanism just at the instuntthc operator is expecting an indication; and th-crc being no way to distinguish between operation of the indication mechanism by indication current properly generated. or by alternating current improperly applied. the indication mechanism. if operable bv alternating current. as Well as direct current. might give a false indication.

Although I have parti ularly described the QIHTISUHCHOII of one physical embodiment of my invention, and explained tln operation and principle thereof: uererllu a h-ss. desire to have understood that the form selected is merely illustrative hut does not exhaust the possible physical mutual ments of the idea of means underlyi my invention.

Vvhat I claim as new and desire to secure by Letters Patent oi the United States.

1. ln an electric interlocking system, the combination with a plurality of functions: each actuated hy an electric motor adapted to he operated by alternating current and to generate direc' current dynuu'iiraily. a source of alternating current, lever for ear h function t-ol'itrolling the connection lit tween said source and the electric motor tllti'tflfl'f, an individual return connection from the motor ot' each function to said source: an indication circuit for each function losed while it is at rest in one of its positions and electromagnetic means in said indication ircuit for curl) function operable by alternat ng cur-rut hut not direct current for interrupting the corresponding return connection from that function whereby whenever current is improperly supplied to any function from said source tending to operate its motor. said electromagnetic means operates to hreelq the return ronnection between that nuitor and the source- Without interfering with the operation of the other Functions.

2. In an electric interlocking system. the combination with a source of alternatirur current, a track, switch, a motor for operating the suitrlu a circuit closed when the switch at rest in one position and including a return connection liietu'een said motor and said source, :1 normally closed circuit controller in said return conntctiou, and e lcctrorcsponsire means 0'? the induction 45 type operated by the flow oi alternating:

current in said circuit; hut not operated in direct current therwin for opening said cin cuit controller and or maintaining it open until manuallr restored. JM 3. in) alternating current rim-trio interlockingsystem cmnprising. in i'ulnlllllzlillflli, a function actuated by an electric motor adapted to he operat-wl hr a:ternatiup current and to germratc direct current dynamically. a source oi' alternating: currcoh a lever: indication mechanism for the lever; circuits controlled by said lever and also in accordalne with the position oi the "fund t'ion. said circuits hcing used tllttl'lliitclf'! tor uunhictino' current from said source to the function 101 operating the motor a. =l tor rond noting itulication current hack from the motor to said indication nieclmnisru o' the lever, said circuits each including a romnion return connection l'ictwecn the motor and said source a circuit controller in said return connection an electroresponsive means for opening said ciruit controller comprising a w nding and :2 in rahle elenient influenced by induction if aiteruatinp nurrent flows in said winding, said Winding being included by the movement oi the lever in said circuits alternately as they are used for conducting indication current.

in an electric interlocking system, of the type in which alternating current is used for (likl'cllllllfl' the functions and direct current is ar ed tor indication purposes, the combination with a lever and indication mechanism thcrctor comprising a movable n'iernhcr. ol electrounagnetic means for operating: said lEltlHllfilZ said means having an operating Winding and a short circuited uiudiug arranged in inductive relation,

wherchy the s stem is protected against false 1udicat:on because the indication magnet will respond to direct current genera-ted dynamically hut will not be operated by the alternatiu current used for operating the function :3. In an ele tric interlocking system, of the type in which alternatiiur current is used or operating" the functions and direct current is u ed for indication purposes, indication mechanism comprising a movable Weu'zljm r. on eiectroniagnet for attracting sail inemher having: two windings arranged in inductive relation; another electro-mag not disguised on the opposite side of said nnimher from said first elem:tro-inagnet,said i'uenelirr hiring? normally closer to the pole llltt tf' oi the second electro-inagnet than to the il'li clcrtroniagnet; and electrical conductors of low rcristance connecting said second eler-tro'inaenet and one of the Windinto oi the lirsl clcctro-iniurnet.

(3. in electric interlocking system con1- pri ion. a source oi alternating current, an elect ically operahlc function, a lever contaoiiiugr the supply of current from said source to the function means arresting the movement of said lever in an indication po siliou. a vi-finally nicwahle plunger actinc when raised to actuate said means to release tlu lower. an armature attacl'ied to said pluna pair oi cores zil'aovs- ,t'ai iii-nurture and spaced tron:- its ends hy equal air gaps. is on said cores. and means on said cores cu the rolls therimn and the armature i which a rrent is induced by the flow of :illrruating rlllltllt in said. coils and thereby opposii *3; the passage of alternating flux through said armature and preventing its upward attraction.

7. Au interlocking system comprising a source or alternating current, an electrically oL-rrahle function, a lever and control cir clots ior governing: the supply of current tron; saio source to the function, and indication nierhanisni for said lever operable by di ect current but not alternating current, said iruliration mechanism comprising a spring-pressed latch. a (log for retaining the latch in its holding position. a plunger tor tripping the dog to release the latch, and electro-magnetic means for operating the plunger.

8. In an electric interlocking system of the type in which alternating current i used for operating the functions and direct cur rent for indication purposes and in which the indication circuits include the motor of the function and a common return connection, the combination with said indication circuits of indication mechanism responsive to direct current but not to alternating cur rent and included in said indication circuits alternately and a separate cross protection device responsive to alternating current but not to direct current and also included in said indication circuits alternately for gov erning the continuity oi said return connection and the indication circuit in which said device is then included.

fl. In an electric interlocking system of the type in which alternating current is used For operating the functions and direct current for indication purposes and in Which two Wires extending from the function to its controlling lever are alternately used with a common return connection to form hoth the operating circuits and the indication circuits the con'lhination nith said indication circuits ot an indication magnet respi'insive to direct current hut not to alternating current. aid magnet comprising a pair ol cores and an armature normally spaced at its ends from said cores by equal air gaps.

10. In an interlocking system in combination: a. source of alternating current; an electrically operated function adapted to generate a direct current e'lynamically after each operation; a deenergized circuit which is closed when the function is at rest; and menus for interrupting said circuit when alternating current flows therein; said means not heing atl'ected by direct current.

ll. In an interlocking system. in combination: a source of alternating current; an electrically operahle "function adapted to generate a direct current dynamically after each operation; a return connection from said function to said source of ci'lrrent: an indication circuit including said return connccl'ion which is closed when said function has operated and is at rest: a circuit controller arranged to interrupt said return connection; and electromagnetic means operahle hy alternating current and not by clircct current and interposed in said indication circuit for controlling said circuit controller.

18.. In an interlocking systenn in combination source of alternating current: an electrically operated t'unction adapted to generate a di ect current dynamically iilie each operation; a return connection iron said function to said ource of current: a circuit which is closed when said function is at rest; elcctromagnctic means o-peralile hy alternating current and not hy direct current for interrupting said return connection when altcrating current liows in said circuit and means for maintaining said electronnnr netic means in its operated condition after it has been initially operated.

13. In an interim-king system. in conihination: a source of alternating current: an electrically operahle function adapted to generate a direct current dyi'ianiically afte each operation: a circuit controlling icrcr for controlling said t'unction: indication mechanism for said lever; a circuit including said indication mechanism which is losed when said Function is at rest; and means rcsponsive to alternating current lint not to d rect current included in said circuit 'lor mal ing a hru k in said circuit and For |uain taining aid hreak until maiuially restored ll. In an interlocking systenn ilm'tlilllllltltion: a source of alternating current: an electrically operahle function adapted to generate a direct current dynamically after each operation; a return connection from said t'nnction to said source of current :ir indi ation circuit in luding said return connection which is closed when said tunction has o cra tcd and is at rest a circuit controller arranged to interrupt said return connection: an alternating current rel: y in luded in said indication circuit for operating said circuit controller; a stick circuit tor said relay which is automatically closed when said rclay is operated: and manually cpcrahle means for interrupting said stick circuit and said return connection siuu ltu:ieonsly.

l5. In an interlocking system for rail roads in combination: a sour'e of alternat ing current; a function adapte to he o erated to either oi two ditl'crent positions: on electric motor oper-atiwly connected to the Function and adapted to he operatei'l hr alternating curren: and to generate direct current dynzunically: control circuits tor the Function including a common return con nection: a circuit controlling lerer at a distant point For controlling the connection lietwecn the control circuits and said source oi current: a partial circuit: clectroniagnetic means responsive to alternating urrent hut not to direct current flowing in said partial circuit tor interrupting said common return connection: and means controlled hr saii': lever for including said partial circuit in each control circuit in turn when the other control circuit is connected to the source of en rreni'.

16. In an interlocking system for rail roads. in comhination: a source oi alternating current; a Function actuated hy an elec lll electromagnetic means responsive to alternating current but not to direct current for opening said circuit controller and maintaining it open unti manually roetorwl: whereby when the function i:-' at rest current from said source improperly supplied to the operating circuit for the H93? position of tinfunction will automainull iutcirupi it own circuit by causing ope rinu of aid clectro-niagnetic means. I

22. In an interlocking system or railroads. in combination: a ource of alternating current: a function at a distant point actuated by an electric motor adapted to be operated by alternating current: operating circuits for the motor including a common return connection: clcrtroinuLi'uctir means responsive to alternating urrent for interrupting said return connection and for maintaining it open until manually re stored; manually operable restoring means for said electro-magnetic means acting to break said common return connection at another point when operated: and means for establishing a circuit for each position of the function which includes the motor and said electromagnetic means and which is closed when the function is at restv 23. In an electric interlocking system of the type in which alternating current is used for operating the functions and direct current for indication purposes, and in which the indication circuits include the motor of the function and a common return connection. the combination with said indication circuits. of electromagnetic means included in said indication circuits and responsive to alternating current but not to direct current. and a circuit controller operated by said means and included in said common return connection.

24-. T11 an electric interlocking system of the type in which alternating current is used for operating the functions and direct current for indication purposes and in which the indication circuits include the motor of the funct on and a common return c011- necton, the combination With said indication circuits. of a single elementaltcrnating current relay included in said indication circuits and circuit controlling means governed by said relay for interrupting said return. connection.

25. In an electric interlocking system of the type in which alternating current is used for operatin the functions and direct current for indication purposes and in which the indication circuits include the motor of the function and a common return con nection, the combination with said indication circuits, of an electromagnetic device included in each indication circuit and responsi ve to alternating current but not to direct current and circuit controlling means operated by said device for interrupting said common return connection and for maintaining such interruption until manu ally restored.

26. In an electric interlocking system of the type in which alternating current is used for operating the functions and direct current for indication purposes and in which the indication circuits include the motor of the function and a common return connection. the combination with said indi cation circuits. of a single element alternating current relay included in said indication circuits, and means governed by said relay for interrupting said common iLiilii! connection and the corresponding indication circuit.

27. In an electric interlocl-zing system of the type in Which alternating current is used for operating the functions and direct current for indication purposes and in which the indication circuits include the motor of the function and a common return connection, the combination with said indication circuits. of electromagnetic means responsive to alternating current for interrupting said return connection, and a circuit automatically established when the function is at rest and including the motor, said electromagnetic means and said return connection. whereby when alternating current is improperly supplied to the motor of the function at rest, such current will cause operation of the electromagnetic means and will autmnatically inter 'upt its path through the motor.

28. In an electric interlocking system for railroads, in combination: a source of altei noting current; a function; a motor adapt ed to be operated by alternating current for actuating said function: control circuits for the motor: means respcmding to the movements of the function for controlling the connection between the control circuits and the motor, said means establishing an electrical connection to the motor in each position of the function which supplies current to the motor to more the function to its other position circuit controlling means associated with each function of the system and included in the path for the flow of current from said source to the motor of that function. said circuit controlling means when operated remaining in that condition until restored; and means operated automatically when alternating current from said open source is improperly supplied to the motor when the function is at rest for opening said circuit controlling means.

29. In an interlocking system for raiiroads, in combination: a source of alternating current; a function actuated by an electric motor With a single series field adapted to be operated by alternating current and of magnetism in its field element to geuci'nte capable retaining; sutiicieni renidwil direct current dynamically: nniniiziily ron trolled means at a point distant from :he function for gorernin; the supp cnrrent from said source to the norm indication mechanism. at the distant po. A limtion circuits for said mechnniem inclu lincf conductors extending from the distant point to the function; and cumin; eutuinatically controlled by the movement of the fun tion For dis onnecting Enid motor from the source of current and connecting it With its wroulure connections reversed with reepe single field into the correspi'miiin iu iwition circuit wherelrv the function may he perated l will from he di tuut point in. alternating current and after each operation will send heel; to the distant point dire t. current. generated drnmuienlly for (H Hf'llil ing the indication mechanism.

iii]. in an electric interlocking V--i'i,"in for 'ziilroiids. in 'onihiinition: u eonri'c of '|Ill( noting current: 11 function; :1. motor for 2!"- tnnting eoid function and adopted to he operated by alternating" 'ui're ui and upoldc of retaining sutticient li'Hl'lllill. IHliQHOllL- TH in its field element to generate direct current dynamically; a. lever {it a distant point for controlling the function; control wires for the function: pole ohiingger mechanism operated :nitonniticully in accordance with the moveinente of the function for rereraing; the connections to the armature of the mo tor and for alternately connecting the motor to Said control wires; indication mechanism for the lever: a d circuit controlling IHLQUQ operated by the lever for olt rnntel connecting said control when in circuit on with the source of current and the other with said indication mechanism wherein the function may he operated Ell will from the distant point by :ilternnting current not! after each operation will Ffllltl hack to the distant point direct current generated dynJinn-all} for operating; the indio-ition mechanism.

31. In :in electric interlocking SKY-loin for roilrozule. in eoinl'iiniition: :1 source of illlfil" noting current: :1 function; :1 series coo pensated motor adapted to he operated In alternating current; and capable of retirining snliicient residual imignetiem in it? field element to genernte direct current dyneimh rally: operating mechanism connecting the function and the motor and permitting tree rotation of the armature of the motor hf. its acquired momentum at the end of en rh movement of the function; a. lever for con trolling' the function; indication niechonism for the lever; and means inclndin: circuit controlling devices operated in accordance with the movement of the turn-- tion and said lever for establishing an operating circuit and an indication circuit for each position of the function: the operiitim; circuit for each poeition of the function including Said source of current and the mo tor. and the indication ii'ircuit for the more. spondino position of the 'tunetion includin the indii'ntion mechanism and the motor ith its tiillllilile connections reversed.

3:1. in in elwt ic interlocking elem for ruilr iids. iii roinhinetion: .1 s urce f alien noting; i urrent: n function: :i lnoun enluple to he ()])(*l:il(l lit :ilternntin; current inn czipiihle of retaining entlirient rceiil nil mun-- in tinni in in h ld element t geuci'ite lilrecl urrent lyllfllllll'lllltl flglil'illll'lgj' llltt'lll lllHlH connecting the function fill'l the motor and permitting i'ree rotation i the armatur ot' the motor after each movemeiri oi th" function: control wires for El e function for ron lneiing holh operating and indication currents; pole changer llll't'lillllli-illl operated in :ici'*or |nnce with the movement of th function for conne ting: the motor ::lte Hillel) to Hitlll ontrol wirce and for rcvciw log the 'fllllilil iill' to the nruriture oi the motor: cll-i-troi lfflll h for operating: n'lllil pole changer on "winning and niezine for incluiling one o the electrom:ignetn in parollel with the motor in each position of the function.

fill. An interlocking system comprising ii nource f alternating current. :1 function operated hy LII] electric motor opernlile on alternating current and adapted to generate direct current dynamically. indication methonieni operable 1*) direct current hut not :ilternzning current. indication circuits for .-tll l iucclniui in. and nieiinsi operated unto n'niticzilly in :n-corilence with the movement ol' the function for alternately connecting the niolor .'ih lie :iim tu'ic nni'llieldtfonncelions I'Ov'll'hPl in Rilltl iudlr'ntion circuits-a in tliru :it the compl tion of ea h operation oithe function.

ll. in in!erlocltinr n etem comprising: :1 nourcc of alternating current. switch oper- :iting' i'neclninisin. o. neriee motor with a sino'le field for operating said mechfiniem. 1 lever and ontrol ircuits for governing the motor t'roni :2 distant point, and on indicir tion nnignet associate-st with the lever and operzihle by dire t current hut not alternal.-- ing current. nd means for :intomaticallr connecting the indication magnet in serie with the field and :irnmtin'e of the motor at the end of each operation of the mechanism.

:15. Jill interlocking: system comprising. in combination with n lever. indication mocha-- lllSlll for the lever. an indication magnet opcrzilile on direct current lint not nlternnt inn current for actuating said mechanism. end :1. safety magnet odapted when energized to prevent operation of Said mechanism by the indication magnet.

lea-2 68s fifi luclication .rnechanism for inter-lo uin gi r steins employing alternating current forappergiting and direct current {for indies tioprcomprising a movahle a rmature. and. ..n indication magnet and :1 safety magnet ha ing opposing influences on said armature. 'theindication magnet being responsive when energized by diri t current but not ,alternating current.

Indication m han sm, or interlocking systems crnplo zing alternating current for pper -itingaml direct current for indication, .comprisinga pair of cores and a hack yoke. a movable armature norn'ial'ly spaced at its .ends romsaid cores with equal airgaps. an

operatingwinding onieach core. and a windingioneach core ncluded in closed circuit- .and clisposed hetiveen the corresponding operatingiwiinding and the armature.

w :38. Aninte lockingsystemeinploying 21liG1-- .ijatingcuurentfor operating and d rentcun Went elibr indication, icon'iprisinga smircc of A ternatingcurrent. an electrically operable function. .alever controlling the supply of 25 ourrent from saicl source toithe tuuctioiuan zintlioa-tiioncircuit. and separate indication.

mechanism and cross protection means included n the indication circuit. the. indication mechanism lacing operable by direct current and the cross protection means by alternating current.

39. An interlocking system employing alternating current for operating and direct current for indication. comprising in comhination with an electrically operable function and an indication circuit closed when said function is at rest. separate indication and cross protection devices included in said circ it and operahle only by direct current and alternating current respectively.

ln interlo king system employing alternating current for opcratinc and direct cu rent for indication. comprising in combination with the indication circuits and the common return connection of the system. in

dicatiou mechanism operahlc hr dire t current but not. alternating current. circuit coir trolling means for interrupting the ommon return connection. and a single. element a ternatincr current relay for governing said circuit controlling means.

ll. \n int rlocking system employing alternating current for operatiml and direct urrent tor indication. coi'uprising an P ow-- tri ally opcrahle function. e. our e o alt u n ting urrent. lercr controlling the supp y" it c rrent from said s urce t th" tum li n. indi at on i nhaui lu th an indication circui then-tor. circuit com (50 tro l ng means upcrahlc r alt rua in r ui rent hut not dir ct urrent For interruptiznr h s pply t urrent to thfunction from said source. said circuit cout ollinfl means when operated continuing in that condition until restored. and ntanua lly operable means for restoring the ,cincuit controlling .means t2. An interlocking system .employing al targeting current foropergting and direct curren iOr indication. coniprisinga .func- .tion. a source of alternating current. ,a return connection from thcifunc tion to the s airce. a circuit closed when the function is at rest, electrically operable circuit control ling means for ilgreaking the return conne .tion when alternating. current flows in said circuit, saichcircuait controlling means when operated continuing in operation until re stored. .and a manually operable restoring device for the ,nicui't oontrnlling .ipeaus adapted when active to also hreak the re .turn conneotiom 43. An interlocking system comprising a function, ,asource of: alternating current. a returnconnection from the #Eunotionto the source, a circuiticlosed when the function is lat: west. ,acimuit controller in .the .return connection, .aisingle element alternating current relayoperating when cur-cent flows in Said circuit toopen ithe oLrcui-t controller.-

and 'towholdw it .iepen .unt'il uestoued. and

means for l restoring-r isaid cir ui c ntroll r acting when operated to interrupt the re:

turn connection at another point.

45. An interlocking system comprising a function. a source of alternating current. a return connection from the function to the source, an indication circuit including in part said return connection and closed when the function is at rest. and electro-responsiye means governed by the flow of alternatin; current in the indication circuit for breaking both the common return connection and the indication circuit.

46. In an interlocking system of the type in which alternating current is used for operating and direct current for indication. normal and reverse indication circuits closed When the function is at rest. and electro responsive means pcrahle hy alternating current hut not direct current and alter natcl included in said circuits for orcaking the existing indication circuit.

47. ln an interlocking system. a plurality f functions and circuits therefor closed when the respective functions are at rest,

a source of alternating current, individual return onnections from said functions to the source, and electro-responsive means in each of said circuits operable by alternating current for breaking the corresponding return connection to said source without interp jr the supply of current from said -our-e to the other functions.

48. .\n interlocking system comprising a plurai tv of functions operable by alternating current and adapted to generate direct current dynamically after each operation, :1 circuit associated with each function and closed when that function is at rest. and individual cross protecion devices included in the se eral ircuits and o 'ierable Upon alternating current but not direct current.

49. An interlocking svstem in which alternating current is used for operating and direct current for indication comprising, a lever. indication mechanism for the lever operable on direct current but not alternating current, indication circuits for said mechanism. an indication selector controlling said circuits and a cross protection device included in the indication circuits and operated by alternating current but not dition for opposing rect current for preventing application of current to the function when alternating current flows in the indication circuits.

50. An interlocking system in which alternating current is used for operating and direct current for indication comprismg, a lever, indication circuits having G a common path, indication mechanism. for

function, a lever, indication mechanism for I the lever including an indication magnet operable by direct current but not alter nating current, a safety magnet responsive to the flow of operating current to the functhe indication magnet, indication circuits or supplying current to the indication magnet, and an indication selector for selectively establishing said circuits.

JOHN C. LINDNER. 

